Dissection of lin-11 enhancer regions in Caenorhabditis elegans and other nematodes.
The Caenorhabditis elegans LIM homeobox gene lin-11 plays crucial roles in the morphogenesis of the reproductive system and differentiation of several neurons. The expression of lin-11 in different tissues is regulated by enhancer regions located upstream as well as within lin-11 introns. These regions are functionally separable suggesting that multiple regulatory inputs operate to control the spatiotemporal pattern of lin-11 expression. To further dissect apart the nature of lin-11 regulation we focused on three Caenorhabditis species C. briggsae, C. remanei, and C. brenneri that are substantially diverged from C. elegans but share almost identical vulval morphology. We show that, in these species, the 5' region of lin-11 possesses conserved sequences to activate lin-11 expression in the reproductive system. Analysis of the in vivo role of these sequences in C. elegans has led to the identification of three functionally distinct enhancers for the vulva, VC neurons, and uterine pi lineage cells. We found that the pi enhancer is regulated by FOS homolog FOS-1 and LIN-12/Notch pathway effectors, LAG-1 (Su(H)/CBF1 family) and EGL-43 (EVI1 family). These results indicate that multiple factors cooperate to regulate pi-specific expression of lin-11 and together with other findings suggest that the mechanism of lin-11 regulation by LIN-12/Notch signaling is evolutionarily conserved in Caenorhabditis species. Our work demonstrates that 4-way comparison is a powerful tool to study conserved mechanisms of gene regulation in C. elegans and other nematodes.
Marri
Sujatha
S
Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada.
Gupta
Bhagwati P
BP
D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D002107:Caenorhabditis / Q000196:embryology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D017173:Caenorhabditis elegans / Q000196:embryology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics* / Q000502:physiology; D019070:Cell Lineage; D004742:Enhancer Elements, Genetic; D005260:Female; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics* / Q000502:physiology; D008969:Molecular Sequence Data; D009474:Neurons / Q000502:physiology*; D051880:Receptors, Notch / Q000378:metabolism; D013045:Species Specificity; D014844:Vulva / Q000196:embryology / Q000254:growth & development / Q000378:metabolism
D029742:Caenorhabditis elegans Proteins; D018398:Homeodomain Proteins; C111267:Lin-11 protein, C elegans; D051880:Receptors, Notch